sumpter250superelevation!!! In the prototype, the outer rail of a curve is placed fractions of an inch higher than the inside rail to force rollingstock to lean inwards, compensating for the tendancy to lean outwards at speed. The train can take the curve at higher speed. Model trains DON'T lean outwards on the curves,(unless they're moving at warp 8),and ,in fact tend to be pulled into the curve. Superelevation increases this tendancy, and,if the curve is tight enough, as model curves tend to be, the train can be pulled right off the track! This is especially true of auto racks, and double stacks. Looks good!,,,, not recommended.
Above is a quote from an earlier post, the following is my response:
I have a question too. For code 83 track, what would be the height of the outside rail prototypically? How high is it on the prototype, and how high would that be in actual inches to get the correct scale height?
I'm beginning to realize that Windows 10 and sound decoders have a lot in common. There are so many things you have to change in order to get them to work the way you want.
For almost all applications of super-elevation in HO, about the thickness of cardstock is almost going to be too much. I use the clear bubble pack plastic in packaging. I cut strips of it and place it under the edges of the ties on the outside rail on a curve. It looks good. I find that a few people, not many, over-do the super in HO.
Here's what mine looked like with no strips...the sub-roadbed was MDF spline that was canted and planed:
BNSF UP and others modeler I have a question too. For code 83 track, what would be the height of the outside rail prototypically? How high is it on the prototype, and how high would that be in actual inches to get the correct scale height?
First, superelevation does not depend on what code of rail is used. For the prototype the outer rail is usually limited to three inches above the inner rail. I have found that this amount of superelevation in the model looks very realistic. Too much is worse than too little, as it starts to look "toy like". So for HO scale (87.1:1) the outer rail would be raised 3/87.1" which is 0.034 " (about 1/32") above the inner rail. I lay a digital level across the rails to measure superelevation tilt angle. It turns out that a pretty accurate relationship between the angle, in degrees, the rail height difference, and the track gauge in inches is : tilt angle (deg)=57.3 x rail ht difference/ track gauge. So, for the prototype with a track gauge of 56.5 " a rail height difference of 3" results in a tilt angle of 3.04 degrees. For low speed track such as sidings the superelevation should be about half as much to look right.
On my eased and superelevated 60" curves, I achieve full superelevation with .040 Evergreen strips under the outside end of the ties. This gives a 2" elevation to the outer rail. I use steadily diminishing shims under the eased section of track.
To me, it looks perfect. It's not so much that it calls attention to it, but you still "see" it.
I can recall no derailments on these curves.
Here, by the way, is a short and interesting discussion on superelevation:
https://www.trackplanning.com/superelevation.htm
As I said, I think 2" is perfect for my trackage. I will mention that it represents a single track Western main line. So trains might move briskly, but not blindingly. I MIGHT raise the rail a bit more if I was running a lot of high speed passenger. Probably would, actually.
Ed
Thanks!
I agree with your choice for the following reasons:
If you are placing the shim under the ties at a point directly under the outer rail then the tilt point of the ties is probably at the far end of the tie, which is not under the inner rail. By my measurement, for a standard 8 1/2 ft. HO tie, this point is 0.947" from the outer rail so I calculate that your tilt angle is actually 2.42 degrees (57.3 x 0.040/0.947) which is about a 2 1/2" prototype rail height difference. This is right at the ideal superelevation from my experience. Plus or minus a half a degree is very hard to notice by eye.
IIRC, I used 0.02 or 0.03" styrene strips for my superelevation. Enough to be noticed but not too much if my trains were stopped on the curves for some reason. I also eased the superelevation into and out of the curves in height incriments of 0.01" at a time for a determined length of track.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
jharrison I agree with your choice for the following reasons: If you are placing the shim under the ties at a point directly under the outer rail then the tilt point of the ties is probably at the far end of the tie, which is not under the inner rail.
If you are placing the shim under the ties at a point directly under the outer rail then the tilt point of the ties is probably at the far end of the tie, which is not under the inner rail.
Ah, but I am not. As I said, I placed the .040" shims under the outer end.
By my measurement, for a standard 8 1/2 ft. HO tie, this point is 0.947" from the outer rail so I calculate that your tilt angle is actually 2.42 degrees (57.3 x 0.040/0.947) which is about a 2 1/2" prototype rail height difference. This is right at the ideal superelevation from my experience. Plus or minus a half a degree is very hard to notice by eye.
(track gage) / (tie length) X (shim thickness) = superelevation in true inches
.7" / 1.2" X .040" = .023"
Convert true inch to HO inch: .023" X 87.1 = 2.03" HO
I certainly agree the difference isn't stunning. I just didn't want people thinking I was shoving the shims underneath the rail. That's too much like, man, work. According to Maynard G. Krebs, anyway.
My mistake, I read that as under the outside rail where you actually said under the outside edge of the tie. Sorry, but we still are in agreement and in fact most of my curves also use closer to 2 degrees than 3, although 3 looks good also.
For those of you considering adding superelevation, note that it has to happen "gradually". You can't just be going along flat, and then kick up the outside rail. For my curves, it takes 18" to go from flat to full superelevation. Which, conincidentally, is how long the easement is, also.
Other folks I've conversated with use 12". I prefer the longer distance.
Trains, real and model, don't like physical surprises. Gentle does it.
Good to know. I was wondering about that too.
I use multiple layers of 1/4" masking tape under the outside rail.
The tape is roughly .004" thick per layer, so the six layers I use gives about .024" of height over the inner rail. This looks about right.
The advantage of this method over other shims is that no tapered shims have to be fabricated. I start with one layer of tape, then the next is offset 1.5" into the first strip, and so on for all six strips. It builds a gentle nine inch long ramp that none of my equipment has a problem with.
Mark P.
Website: http://www.thecbandqinwyoming.comVideos: https://www.youtube.com/user/mabrunton
I've been attempting to open a Word document that outlines my method of adding superelevation, with no success. I copied the following from another thread, which pretty-much explains the process. The method discussed is for cookie-cutter style plywood roadbed, and deals with track on a grade, but the method works for level track, too:
"For the riser-supported track, I had all of the risers clamped to the benchwork crossmembers, with a pencil line on each denoting the proper height to keep the rise of the grade constant. I then selected the riser closest to the middle of the curve, and after placing a locomotive on the curve, carefully removed all of the clamps. I then lifted that centre riser to approximately its proper height, and pushed its bottom end towards the outside of the curve. When the angle of superelevation "looked right" on the locomotive, I aligned the inside end of the pencil line on the riser with the top of its joist, and re-clamped it in place.
Because all of the other risers were not fixed to the benchwork, the 3/4" plywood roadbed (about 2" wide) flexed torsionally when that centre riser's bottom end was pushed out, but the amount of cant decreased as the distance from the centre riser increased , automatically creating easements into and out of the superelevation. All that was left to do was to lift each riser, in-turn and without changing its newly created angle of deflection, until the inside end of its pencil line was was even with the top of the joist to which it was to be fastened. It's actually easier to do than it is to explain."
Wayne
Tilting the risers or or cutting a taper on the top (both directions on grades) is what I've done for years but for some reason most don't like it. The beauty of this is that I can change the tilt or elevation if something doesn't look right. With shims you better get it right the first time.
jharrison Tilting the risers or or cutting a taper on the top (both directions on grades) is what I've done for years but for some reason most don't like it. The beauty of this is that I can change the tilt or elevation if something doesn't look right. With shims you better get it right the first time.
Ballasting is what seals the deal, with the plastic shims I use. Up until then, I can just pry them out.
Fact is, once a person decides the proper superelevation, it's hard to avoid getting it "right the first time."
My curves are built on flat plywood. So there are no risers to cant.
Those of us who choose to ballast our tracks soon learn to trial the arrangement using typical consists before applying the ballast. It typically takes me a couple of weeks of running trains and then tweaking rail heights before I dare to groom and glue the ballast.
Hello all,
I use wooden coffee stir stick that are 6/64-inches thick, 5/32-inches wide and 5-1/2-inches long.
On my pike I use sectional track in 15-, 18- and 22-inch radii.
To superelevate the curves I cut the stir sticks into 1-inch pieces and place three pieces, evenly spaced, on the outside of the curve.
For transitions back to level track, on the last piece of sectional track, I don't place any pieces of stir stick, but rather build up the ballast.
Once the ballast is set and dried the transitions are stable.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
jjdamnit use wooden coffee stir stick that are 6/64-inches thick, 5/32-inches wide and 5-1/2-inches long. On my pike I use sectional track in 15-, 18- and 22-inch radii. To superelevate the curves I cut the stir sticks into 1-inch pieces and place three pieces, evenly spaced, on the outside of the curve. For transitions back to level track, on the last piece of sectional track, I don't place any pieces of stir stick, but rather build up the ballast.
6/64" equals more than 8" in HO scale. That's a lot compared to what many experienced modelers use for much broader curves. And if you are only allowing at most 9" for the superelevation to run off, that's a lot of twist across a short length of track, not to mention the vertical kinks on the elevated rail.
Are you sure that's the amount? Can you post a photo to show how it looks?
In an earlier thread, you gave the amount as 1/32".http://cs.trains.com/mrr/f/11/t/259681.aspx
jjdamnitIn the May 2015 edition of Model Railroad Hobbyist magazine; page 33, there is a Q&A regarding superelevation. The recommendation from MRH is that it should not exceed 1/16-inch (1.5 mm) for HO scale. On my flat curves I use 1/32-inch (0.75 mm) thick wood coffee beverage stirrers on the outer edges.
For such sharp curves, superelevation has been often found to be a reliability headache.
Layout Design GalleryLayout Design Special Interest Group
cuyama jjdamnit use wooden coffee stir stick that are 6/64-inches thick, 5/32-inches wide and 5-1/2-inches long. On my pike I use sectional track in 15-, 18- and 22-inch radii. To superelevate the curves I cut the stir sticks into 1-inch pieces and place three pieces, evenly spaced, on the outside of the curve. For transitions back to level track, on the last piece of sectional track, I don't place any pieces of stir stick, but rather build up the ballast. 6/64" equals more than 8" in HO scale. That's a lot compared to what many experienced modelers use for much broader curves. headache.
6/64" equals more than 8" in HO scale. That's a lot compared to what many experienced modelers use for much broader curves. headache.
.7" / 1.2" X 6/64" = .0548"
.0548" X 87.1 = 4.77" of superelevation
Quite a bit, I agree. What with my choice of 2". On a 60" radius curve.
Don't understand the point of your math. But agree, that doesn't seem like an amount that will operate reliably, whether it's under 5" in HO or over 8" in HO. On a 15" curve.
cuyama6/64" equals more than 8" in HO scale. That's a lot compared to what many experienced modelers use for much broader curves.
I defer to my signature.
cuyamaCan you post a photo to show how it looks?
Still working on how to post photos without going through 3rd party site.
Hoping to post photos to several of my threads soon.
Thank you for all the positive input.
jjdamnitI defer to my signature.
And your own earlier post compared to this one? One of them must be wrong. Right?
The issue is that newcomers read these posts without an appreciation for the poster’s level of expertise. Anyone can post anything they like, but when it diverges so far from best practices, I think it’s important to note that and ask for more information. But that’s just me.
jjdamnitStill working on how to post photos without going through 3rd party site.
You're in luck -- you may post them right on this site. One waits a few days for it to be approved sometimes, but no need to go elsewhere.
http://cs.trains.com/mrr/m/mrr-layouts/default.aspx
On smaller layouts sometimes features are abrupt and compressed.
I am limited to a 4'x8' pike.
OH God, how I would love for even a 5'x9'- -but even that is unobtainable.
cuyama...but when it diverges so far from best practices, I think it’s important to note that and ask for more information.
Again...
I apologize for not having enough room to build a pike that can utilize "best practices" in the mean time I will run my trains on my sub-standard pike and continue to enjoy this great hobby.
Sorry, this doesn’t help.